What spirit is combined with orange juice in a Harvey Wallbanger cocktail?

In a Harvey Wallbanger cocktail, vodka is the primary spirit that is combined with orange juice. This cocktail typically consists of vodka, orange juice, and a splash of Galliano, an herbal liqueur, which adds a unique flavor profile to the drink. Vodka is favored for its neutral taste, allowing the citrusy brightness of the orange juice and the distinctive herbal notes from Galliano to shine through. The combination results in a refreshing and approachable cocktail that gained popularity in the 1970s.

The other options do not fit this cocktail's recipe because rum is typically associated with tropical cocktails, whiskey brings a heavier flavor profile that wouldn't complement orange juice as well, and tequila is more commonly used in cocktails like margaritas. Thus, vodka is the quintessential spirit for a Harvey Wallbanger.